Choosing a Pile Type

Q: Which standards or codes apply?

ACI 318 / FHWA, Eurocode 7; Thai DPT/EIT; ASTM D1143 (static), D4945 (dynamic/PDA), D5882 (low-strain integrity).

Quick pick (TL;DR)

Urban / noise-sensitive / large capacity → bored cast-in-situ.
Highest capacity per cost, good quality control → driven precast/spun.
Marine / very deep / tension → steel pipe or H-pile.
Tight access / underpinning → micropile.
Always confirm with a static or dynamic (PDA) load test and integrity tests.

Step 1 — Type comparison

Type	Best for	Watch out
Bored cast-in-situ	Urban, low noise, large capacity.	Workmanship-sensitive.
Driven precast / spun	Cost-effective, fast.	Noise / vibration.
Steel H / pipe	Marine, deep, tension.	Cost; corrosion.
Micropile	Tight access / underpinning.	Lower capacity.

Step 2 — Capacity & group sizing

Q_u = skin + end bearing; allowable = Q_u/FoS; piles = load ÷ allowable.

Worked example — pile group

Given Column load = 4000 kN Bored pile Ø600, ultimate Q_u = 2000 kN Step 1 — Allowable / pile Q_a = Q_u / FoS = 2000 / 2.5 = 800 kN Step 2 — Number of piles n = 4000 / 800 = 5.0 → use 6 piles (allow eccentricity / group efficiency) Step 3 — Spacing & cap spacing ≥ 3D = 1.8 m c/c design pile cap for the 6-pile reactions

Step 3 — Testing & verification

Static / PDA load test.
Integrity: PIT (often 100%).
Group efficiency < 1 in clay.

Pile group calculator

Allowable load & number of piles

Qa = Qu / FoS, then number of piles (spacing ≥ 3D).

Column load (kN)

Ultimate Qu (kN)

FoS

Pile dia (mm)

Screening — ignores group efficiency, downdrag, lateral/uplift, cap design.

Common mistakes

Driving near sensitive buildings.
Ignoring negative skin friction.
No load test.

Requisition & datasheet

Loads/soil; type, size, capacity, group.
Load/integrity tests; concrete; code.

Frequently asked questions

What should I know about Choosing a Pile Type?

Urban / noise-sensitive / large capacity → bored cast-in-situ. Highest capacity per cost, good quality control → driven precast/spun. Marine / very deep / tension → steel pipe or H-pile. Tight access / underpinning → micropile. Always confirm with a static or dynamic (PDA) load test and integrity tests.

Which standards or codes apply?